Pet owners often travel with their pets. This travel can be as simple as taking their pet to the grocery store, laundry, or the like. The travel can be more complex such as taking their pet with them on a vacation to sending the animal by common carrier.
In the simple case the animal is generally placed in the family car (van or other vehicle) and taken to the destination. A problem is presented whenever the owner wishes to leave the animal in the vehicle. In winter there is no problem as the animal will be able to maintain its warmth through natural actions on its own part. In the summer, there is a major problem for the sun will raise the temperature within vehicle to well over 120 degrees Fahrenheit. This will kill the animal.
Many owners partially roll the vehicle windows downxe2x80x94a process called xe2x80x9ccracking.xe2x80x9d The owner has to crack the windows so that the animal cannot escape and so that a potential thief cannot enter the vehicle. The end result is poor ventilation and the temperature within the vehicle will easily reach 120 degrees Fahrenheit.
Other animal owners often ship their animals by common carrier. For example, dogs are sent to dog shows (or to purchasers by a kennel) and cats are sent to cat shows (or to purchasers). In the winter, again few problems occur, because the common carrier will keep the animal in a fairly warm environment and the animal itself can provide warmth. The problem raises its head, again, in the summer months. Most common carriers will NOT accept animals when the ambient temperature (outside temperature at the airport) exceeds 85 degrees Fahrenheit. The carrier is concerned for the welfare of the animal, for the cage temperature will equal that of the ambient (maximum 85xc2x0 F.); thus, stressing the animal.
Several devices have been proposed and patented which address the problem of controlling the environment of a pet. U.S. Pat. No. 4,899,693 by Arnold discloses a Cooled Pet Bed and uses ice cubes placed within a container underneath an open weave mattress. U.S. Pat. No. 4,939,911 by Mandell discloses a Vehicular Kennel for Pets. This device uses the Peltier effect to cool a kennel within the vehicle. Mandell takes his power from the vehicle, the vehicle battery and/or a solar panel mounted on the vehicle and uses forced air to cool the enclosure. U.S. Pat. No. 5,727,503 by Whittaker discloses a Portable Cooling Kennel System that uses ice as the cooling medium. Ice is placed in a sliding tray underneath the enclosure area and air is drawn over the ice around the enclosure and exhausted at the top. Whittaker discusses xe2x80x9cforced airxe2x80x9d and fans, but never shows how the power is derived. Furthermore, the xe2x80x9cice storage areaxe2x80x9d is limited and the cooling supply will not last long. U.S. Pat. No. 5,887,436 by Duddleston discloses a Portable Cooled Pet Carrier that, like Mandell, uses the Peltier effect to provide cooling for the animal.
U.S. Pat. No. 5,761,992 by Gallo discloses a Portable Animal Storage Unit that is designed to preserve the meat of game animals while being transported. The disclosure mentions that DC power may be used for cooling, but never makes a full disclosure.
U.S. Pat. No. 3,175,534 discloses a pet drying device that uses a restrictive enclosure to house a wet animal while hot air is blown over the animal. The concept could be expanded to blow ambient air over an animal to keep it cool; however, if the ambient air is greater than 85 degree Fahrenheit, the animal will not do well.
All the prior art directly applying to keeping enclosed animals environmentally comfortable, while worthwhile, can only work on paper. No attention has been paid to the size of the Peltier device that would be required to condition an enclosure. The inventors have assumed that power is readily available (which is true in the case of a vehicle, but even in a vehicle the power is limited to some 10 amps at 12 Volts DCxe2x80x94120 Watts). No power is readily available on the tarmac of an airport, in an airplane cargo hold or in a warehouse/baggage facility. Furthermore to properly run a compressor-type refrigeration system it will take at least 1000 watts. Whittaker, while proposing ice as the cooling medium, provides no data as to the length that his device would keep the animal cool. Furthermore, no provision is made for reducing heat transfer.
Thus there remains a need for a working portable air-conditioned animal carrier that will maintain the environment for the enclosed at a comfortable temperature under high ambient temperature conditions and that is easily maintained and relatively inexpensive. The carrier should include a simple fail-safe system that will provide its own source of power for ventilation and have a natural backup if there is a power failure. Finally there remains a need for a system that will operated for at least 12 hours, which is a recognized time period for transporting a animal door to door by common carrier.
The preferred embodiment of the instant invention consists of an insulated outer carrier with internal compartments and a hinged door with ventilation holes. The door may be transparent, translucent or opaque. One compartment is for the animal and the other compartment is used for storing the cooling medium, which is commonly available crushed ice. A heat exchanger is placed at the bottom of the ice compartment. A further compartment is provided for storing ancillary equipment within the container.
A low power electric fan draws air from the outside, through the heat exchanger, into the animal compartment and forces the air out of the ventilation holes in the animal compartment door. A protected switch (one that is not easily turned on or off) controls the electric fan and a lead-gel battery provides power to the fan via a thermostatic switch. The thermostatic switch controls the animal compartment temperature within a narrow range between 73xc2x0 F. and 76xc2x0 F. This range can be maintained with ambient temperatures up to 120xc2x0 F.
Direct current power may be supplied from two sources depending on the use of the instant invention. If local DC power at 12 volts is available (cigar lighter) then power is preferably taken from this source. The alternate source is a lead-gel 12-volt battery that is kept within the device. Both the internal battery and external power may be used at the same time, if required.
The intermittent fanxe2x80x94temperature controlledxe2x80x94makes the ice last at least twelve hours on a full load (20 pounds) of ice. If the fan is turned off and the pet removed, the ice will last at least one full day. Upon a failure of the ventilation system power, the mere fact that the heat exchanger is immersed in ice will cause ventilation air to xe2x80x9cbackflowxe2x80x9d therefore providing air, at ambient temperature to the animal.